/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.extensions.gcp.auth;



import com.google.auth.Credentials;

import com.google.auth.oauth2.GoogleCredentials;

import com.bff.gaia.unified.sdk.options.PipelineOptions;



import java.io.IOException;

import java.util.Arrays;

import java.util.List;



/**

 * Construct an oauth credential to be used by the SDK and the SDK workers. Returns a GCP

 * credential.

 */

public class GcpCredentialFactory implements CredentialFactory {

  /**

   * The scope cloud-platform provides access to all Cloud Platform resources. cloud-platform isn't

   * sufficient yet for talking to datastore so we request those resources separately.

   *

   * <p>Note that trusted scope relationships don't apply to OAuth tokens, so for services we access

   * directly (GCS) as opposed to through the backend (BigQuery, GCE), we need to explicitly request

   * that scope.

   */

  private static final List<String> SCOPES =

      Arrays.asList(

          "https://www.googleapis.com/auth/cloud-platform",

          "https://www.googleapis.com/auth/devstorage.full_control",

          "https://www.googleapis.com/auth/userinfo.email",

          "https://www.googleapis.com/auth/datastore",

          "https://www.googleapis.com/auth/pubsub");



  private static final GcpCredentialFactory INSTANCE = new GcpCredentialFactory();



  public static GcpCredentialFactory fromOptions(PipelineOptions options) {

    return INSTANCE;

  }



  /** Returns a default GCP {@link Credentials} or null when it fails. */

  @Override

  public Credentials getCredential() {

    try {

      return GoogleCredentials.getApplicationDefault().createScoped(SCOPES);

    } catch (IOException e) {

      // Ignore the exception

      // Pipelines that only access to public data should be able to run without credentials.

      return null;

    }

  }

}